Micro Aberration Scatter Index (MASI) as an objective proxy for contrast sensitivity after keratorefractive surgery:...

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• Assessing visual quality after keratorefractive surgery is crucial for patient satisfaction.
• Objective measures are needed to complement subjective visual assessments.
• Wavefront aberrometry provides detailed optical information.

Purpose of the Study:

• To evaluate the Micro Aberration Scatter Index (MASI) as an objective proxy for visual quality.
• To determine the correlation between MASI and functional vision metrics post-keratorefractive surgery.

Main Methods:

• Prospective study of 200 eyes undergoing KLEx, PRK, or LASIK.
• MASI measurement using pyramidal wavefront aberrometry.
• Contrast sensitivity and uncorrected distance visual acuity (UDVA) assessment at 30 days postoperatively.

Main Results:

• MASI demonstrated significant inverse correlations with contrast sensitivity across all spatial frequencies (r = -0.46 to -0.62).
• The strongest correlation was observed at 18 cycles per degree (cpd) (r = -0.62, R²=0.39).
• MASI tertiles significantly differentiated visual performance, including contrast sensitivity and UDVA.

Conclusions:

• MASI is a promising, rapid, and clinically feasible index for optical quality assessment.
• It correlates strongly with functional vision and detects subtle visual degradation.
• Further research is needed to establish its application in mesopic/night vision and multicenter reproducibility.